Draw toggles for spindle male tapers of milling and the like machines



J. c. HOLLIS 2,893,291 DRAW TOGGLES FOR SPINDLE MALE TAPERS 0F MILLING AND THE LIKE MACHINES 3 Sheets-Sheet 1 July 7, 1959 T5. 1- lb INVENTOR. q, dog/Y C. #040 ATTOP/YE) I m L 84 I 4 1 ho I I July 7, 1959 J. c. HOLLIS 2,893,291

DRAW TOGGLES FOR SPINDLE MALE TAPERS OF MILLING AND THE LIKE MACHINES Filed July 20, 1956 :5 Sheets-Sheet 2 INVENTOR. (/O/VA/ C. H0406 y 7, 1959 J. c. HOLLIS 2,893,291

DRAW TOGGLES FOR SPINDLE E TAPERS OF MILLING AND THE LIKE CHINES Filed July 20, 1956 3 Sheets-Sheet 3 a 84 1: iz

IN V EN TOR. JOHN C #04415 ArfOP/YE) United B ttes Application-July 20,1956, Serial No. 599,134

6 Claims. (CI. 90-11) invention relates to draw'toggles-for spindle male tapers of milling and the like machines.

In-application Serial No. 590,485 of SigmundM'. Morey and Secondo -L. Casella, filed June 11, 1956 in Div. 12, and-assigned to the assignee in this application, there is disclosed a power transmission for milling and the like machines including an elongated draw bolt for a male taper. The draw boltin said cope'nding application extend's through the entire spindle. The spindle which is elongated by're'ason of'the fact that the transmission casing together with the spindle are movable up and down and slidable relative to a'co'ne pulley mounted-ona statiohary head. It has been found thata long draw bolt is clumsy and-doesnot operate very well when it is excessive inlength; It isone object of the present invention to improve the structure'as shownin said copending application, Serial No. 490,485.

'Another object'ofthis'invention is-to provide in amilling or the like machine, a relatively short drawbolt (replacingthe long draw bolt shown in said copending application), and highly improved means for quick clamp and release action between the draw bolt and the spindle.

Yet-a further object 'of this invention is to provide in a device of the character described, a highly improved toggletype clampingand release mechanism for clamping the draw bolt and the male taper to the spindleof a machine'tool.

'A' still further object of this invention is to-provide in a devicerofthe character described, a draw bolt which will fit all 'standard'tapers and which is adjustable to suit the position of a male taper, such as a standard ASA #50 taper.

A further object'of'this'invention is to provide'a strong, rugged and durable mechanism of the character described, which shall be relatively inexpensive to manufacture, simpl'e and easy to operate, and yet practical and eflicient to a hi'g'hdegree in use.

Other'objects of this invention will in part be obvious and in' part hereinafter pointed out.

The invention accordingly consists in the features of construction, combinations of elements, and arrangement of parts, which will be exemplified in the construction hereinafter'described, and of which the scope of invention will be indicated in the appended claims.

In' the accompanying drawings in which is shown various illustrative embodiments of this invention:

Fig. 1 is a longitudinal cross-sectional view of the mechanism embodying the invention and showing the draw bolt and male taper spaced from the spindle;

Fig. 2 is a cross-sectional view taken on line 2-2of Fig. 1 and showing the draw bolt in released condition;

'Fig. 3 is a partial cross-sectional view taken on line 33 of Fig. 2;

Fig. 4 is a view similar to Fig. 3 but showing the-draw bolt in clamped condition;

N Fig. 5 is a cross-sectional view taken on line 5-5 of Fig. 4;

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Fig. 6 is a cross-sectional view taken on line 6-6"of Fig. 4;

Fig. 7 is a perspective view of one'of the wedges form:- ing part of the mechanism embodying the invention; and

Fig. 8 is a perspective view of one of the blocks forming part of the mechanism 'embodyingthe invention and connected to one of the wedges by means of a toggle strut.

Referring now in detail to the drawing, 10 designates machine tool mechanism embodying the invention. The same comprises a casing 11 which corresponds to the casing portion 84,. forming part of the-casing 60 in said copending application, Ser. No. 590,485. The casing: 11 is formed with a lower internal bore 12 extending to the lower edge 13 of the casing. At the upper end of the bore 12 is an inwardly extending annular flange 14. Above the flange 1'4'is an enlarged chamber 15. Above the chamber 15 is an internal bore 16. Within the bore 1'2 are ball bearings 18; Attached to the lower end 13 of the casing is a ring 191 The-ring -19maybe attached to the casing by screws 20 or in any other-suitable manner and serves to keepthe ball bearings implace. Within the bore 16 are ball bearings22.

Extending longitudinally through the casing 11 and journalled within the ballbearings 18 and22 is a spindle 23. Said spindle 23 is formed with a longitudinal axial through opening- 24. At its lowerend :it is formed-with a head 25 provided with a tapered'opening 26-to receive a male taper 27, such'a's ASA #SO taper.

The spindle 23 is formed with apair of diametrically opposed through openings'25a of rectangular cross section with curved corners. These'openings are located below the ball bearings 22 and substantially within the chamber '15. Above the slots 25a,- spindle 23 is formed with an axial opennig 27a of less diameter than ithe-axial opening 24. Screwed to=the:taper 27 is the lower threaded end of a short draw bolt 30. The drawbolt may be fixed to the taper 27 by means .of locknut 31. At its upper end, the draw bolt 30 is formed with acentral hex socket 32. It is also formed at its upper end with. an annular outwardly extending upwardly and outwardly tapered frusto-conicalflange 33. The Iflange 33 has an. upper frusto-conical surface 34 surrounding the socket 32, and a lower frusto-conical surface 35 parallel. to the frusto-conieal surface 34.

'Slidably mounted within the diametrically opposed slots 25 are a pair of similar, symmetrically disposed wedges 40 (Fig. 7). The wedges 40 are of vertical, rectangular cross section with curved corners and slide snugly but easily in the slots 25. Each wedge 40 has. side surfaces 41, a top surface 42 and a bottom surface 43. Each wedge is furthermore formed at its inner side with a surface 43a of transverse or horizontal curved cross section. On the upper end of surface 43a and below the upper surface 42, each wedge is formed with a part frusto-conical slot 44. The slot 44 has a lower, part frusto-conical surface 45 conforming generally to the lower conical surface 35 of the flange 33. Eachslot: 44 has an upper, part frusto-conical surface 46 conforming generally to the upper frusto-conical surface 34 of. said flange 33. The height of the slot 44 is, however,

somewhat greater than the height of the flange 33. The

slots or grooves 44 are further'formed with inner surfaces 47 of curved horizontal cross section. The Wedge 40 is formed with a lip 48 .having astraight or flat vertical surface 48a above the slot 44 which lip overhangs the inwardly curved surface 43a.

At the opposite or outer side of each wedge is formeda recess 50. The recess50 is formed by upwardly and;

rearwardly inclined surface 51 extending from a lower flat surface 52, and rising upwardly from the bottom.

cylindrical groove or cavity 52a which may be somewhat less than 270 in angular extent (greater than 180). Extending upwardly from the upper end of the groove 52a is a sharply inclined surface 53 from which extends an inwardly curved surface 54. The surface 54 extends to an outer vertical surface 55 in the plane of the surface 52.

Surrounding the spindle 23 and slidable thereon, is a sleeve or ring 60 formed with an annular external groove 61. 'Ilhe ring 60 is formed above the groove 61 with an inwardly extending annular flange 63 having sliding contact with the spindle, and provided with a pair of diametrically opposed, vertical through slots 64. Below the flange 63 the ring is formed with an internal enlarged diameter forming an inner surface 65. Said ring 60 is furthermore formed with diametrically opposed horizontal bores 66 communicating with the vertical slots or grooves 64. At the outer end of each bore 66 is a counter bore or enlarged opening 67 coaxial therewith. Mounted on the rings 60 are a pair of similar symmetrically disposed, diametrically opposed block 70 (Fig. 8).

Each block 70 comprises a stem portion 71 snugly received in one of the bores 66. The stem 71 is formed with an internally screw threaded blind opening 72 for the purpose hereinafter appearing. Extending from the stem 71 is a block portion 74 having parallel vertical side surfaces 76 substantially contacting the side surfaces 64a of the grooves 64. Portion 74 of each block has an 9 wardly, there is interposed between each wedge 40 and its block 70, a toggle strut 90. Each toggle strut 90 has at one end thereof, a part cylindrical portion 91 received in groove 81 and at its other end a part cylindrical portion 92 received in the part cylindrical groove 52. Between the portions 91 and 92 is an interconnecting portion 93 being formed at one side of the center thereof with inclined surfaces 94 and 95 forming similar angles to the horizontal. Surfaces 94 contact surfaces 74 when the ring 60 is slidably moved downwardly on the spindle, to push the wedges 40 inwardly to the position shown in Fig. 4. Portion 93 is formed on the opposite side of the center thereof with inclined surfaces 99 and 100, similar and symmetrically disposed with respect to the inclined surfaces 94 and 95, and making similar angles to the horizontal when the parts are in the position shown in Fig. 4.

In the position of Fig. 4, surfaces 100 contact the inclined surfaces 51 of the wedges, and the surfaces 74s of the blocks 70 contact the surfaces 51 of the wedges. When the ring 60 is slidably moved upwardly, the wedges 40 are pulled outwardly away from each other to the position of Fig. 2, and such movement will bring surfaces 99 of toggle struts 90 into contact with the surfaces 53 of the wedges and surfaces 95 of said struts into contact with the surfaces 80 of the blocks. Also, as shown in Fig. 2 lips 78 of blocks 70 will nest into curved surfaces 54 of the wedges 40. Thus the angle of rotation of the toggles 93 is equal to the angle between the surfaces 95 and 80 when the parts are in the position of Fig. 4. The ring 60 may be raised and lowered by any suitable means such as a fork 110 received in the groove 61, and the fork may be operated through any suitable lip 78 is a downwardly and outwardly inclined flat surface 79. of inclined surface 74e is an upwardly and outwardly sharply inclined surface 80. The surfaces 79 and 80 are connected by a part cylindrical inner surface 81 of the same diameter as the part cylindrical surface 52 of wedge 40.

It will be noted that the inclination of surface 74e of block 70 is the same as the inclination of surface 51 of'wedge 40. It will also be noted that surfaces 51 of wedges and surfaces 79 of blocks 70 have the same angles to the horizontal and are parallel.

Within the bottom of each countersunk opening 67 is washer 84. Screwed within each threaded opening 72 ofbloc'k 70 is the shank 85 of a screw 86. The shank 85 passes through a central opening in washer 84. The head 87 of each nut 86 is received within countersunk opening 67. g

It will benoted that the flange 33 may enter the slots 44 in the wedges 40. When the wedges 40 are in their inward position close to each other, as shown in Fig. 4, the flange 33 is within the slots 44. As the wedges 40 are slidably moved apart, surfaces 46 contact surfaces 34 which push the draw bolt 30 downwardly to'lower the male taper 27 to release the same. As the wedges 40 are slidably moved inwardly toward each other, surfaces of wedges 40 contact the undersurfaces 35 of the flange 33 and raise the draw bolt for clamping the male taper to the spindle. Such latter position is shown in Fig. 4. In the released position (Fig. 2), the draw bolt and the male taper may be removed through the lower end of the spindle. The draw bolt may be adjusted relative to the spindle by loosening the lock nut 31, turning the draw bolt relative to the taper 27 to the desired position, and then again tightening the lock nut. A Wrench may be inserted into the socket 34 for turning the draw bolt relative to the taper.

- In order to move the wedges 40 inwardly and out- Extending upwardly from the inner end lever, not shown. v

It will now be understood that instead of having an internally long draw bolt extending through the entire spindle, a short draw bolt may be employed, and it may be moved to clamping and releasing positions by the toggle means shown.

It will thus be seen that there is provided a device in which the several objects of this invention are achieved H and which is well adapted to meet the conditions of practical use.

v slidable within said spindle, a frusto conical flange formed on said draw bolt, said spindle being formed with opposing slots, wedges slidably received within said slots and formed with frusto conical grooves cooresponding to and adapted to receive said frusto conical flange on said draw bolt for causing sliding movement of said bolt relative to said spindle, a sleeve member surrounding said spindle and concentric therewith, blocks mounted on the inner surface of said sleeve, the inward surfaces of said blocks being formed with part-circular cavities, said wedges formed in their outward surfaces with partcircular cavities, said cavities in-said blocks and wedges having peripheries greater than 180 and less than 360, toggle members each having a central shank portion and enlarged rounded end portions, each corresponding block and Wedge having a toggle disposed therebetween, with one enlarged rounded end of said toggle rotatably journalled within the part-circular cavity of the block and the opposite enlarged rounded portion of the toggle rotatably journalled within the part-circular cavity of the to move the draw bolt in one direction, and whereby movement in another longitudinal direction of said sleeve will cause said wedges to be pulled outwardly to move the draw bolt relative to thespindle in an opposite direction.

2. In combination, a spindle formed with a central longitudinal opening and with opposed slots, wedge members slidably received in said slots, the outer surface of each wedge member being formed with a cavity of angular extent approximately 270, a sleeve coaxial with said spindle and movable longitudinally relative to said spindle, said sleeve being formed on its inner surface with cavities corresponding to the cavities in the outer surfaces of said wedges, a toggle link interposed between each pair of cavities in said wedges and outer cylindrical sleeve, said toggle links formed with a central shank portion and rounded outer end portions, said rounded end portions received within the cavities of said wedges and said sleeve so as to be rotatably locked therein, whereby when said sleeve is moved from one position relative to said spindle to a second position, the toggle links will rotate relative to the cavities in the sleeve thus pushing the wedges inwardly in the slots of the spindle, and when the sleeve is moved from the second position back to the first position the toggle links will again rotate in the opposite direction, thus drawing the wedges outwardly of said slots in said spindle.

3. In combination, a spindle mounted for rotation about an axis, said spindle formed with a central opening, a draw bolt receivable within said opening, said spindle formed with opposing slots, wedges slidably received within said slots, and adapted to clamp said draw bolt upon sliding inwardly in said slots and to release said draw bolt upon sliding outwardly in said spindle slots, the outwardly facing end surface of each wedge formed with a part-circular cavity, said cavities being approximately 270 in angular extent, a sleeve member surrounding said spindle and concentric therewith, the inner surface of said sleeve being formed with inwardly projecting portions corresponding to said wedges, said inwardly projecting portions of said spindle formed with cavities corresponding to said cavities in said wedges, toggle push and pull links interconnecting each wedge cavity and corresponding sleeve cavity, said toggle links being formed with enlarged rounded ends so as to be joumalled by said cavities and be partially rotatable therein, said sleeve being movable longitudinally relative to said spindle, whereby said toggle links will push said wedges inwardly in said spindle slots upon movement of said sleeve in one direction, and said toggle links will pull said wedges outwardly in said spindle slots upon movement of said sleeve in the opposite direction.

4. The combination of claim 3, said inwardly projecting portions of said sleeve being partially received within said spindle slots.

5. In combination, a spindle mounted for rotation about a longitudinal axis, said spindle being formed with a longitudinal opening and with a plurality of transverse slots intersecting said longitudinal opening, wedges slidable in said transverse slots, said wedges being formed with inward end surfaces and outward end surfaces, the

outward end surface of each wedge formed with a transverse concave recess, the inward end of each concave transverse recess formed with a transverse part-cylindrical cavity, the portions of said transverse groove adjacent said transverse cavity being flat, a plurality of toggle links, said toggle links being formed with a central stem portion having two pairs of opposed parallel sides and part-cylindrical end portions, one portion of each toggle link being received within the part-cylindrical cavity of a wedge, a sleeve surrounding said spindle and concentric therewith, said sleeve formed with inwardly projecting portions adjacent said wedges, said inwardly projecting portions being formed with inwardly curved lips, a partcylindrical cavity formed between said inwardly curved lips and said lips formed with flat portions adjacent said cavity, the outer rounded end of each toggle link opposite the end received in the wedge being received Within the cavity of the inward sleeve projection thereadjacent and between the curved lips thereof, said curved lip portions of said inward sleeve projections being partially received within said concave transverse recesses of said wedges, and means to move said sleeve longitudinally relative to said spindle, whereby said wedges will be pushed or pulled in said transverse slots by said toggle links depending on the direction of movement of said sleeve, and the movement of said sleeve will be limited by the flat parallel walls of said toggle links bearing on the flat walls adjacent the transverse part-cylindrical cavities in said wedges and said inwardly projecting lip portions of said sleeve.

6. In combination, a spindle for a milling machine mounted for rotation about a longitudinal axis, said spindle being formed with a central longitudinal opening for receiving a draw bolt, said spindle being formed with transverse slots intersecting said central opening, wedges slidable within said transverse slot and adapted to clamp a draw bolt in the central opening of the spindle, upon being moved inwardly in said slots, an outer sleeve concentric with said spindle and movable longitudinally relative thereto, said wedges being interconnected with the adjacent portions of said outer sleeve by toggle links, each of said toggle links being connected at one end to a wedge and at the other end to an inwardly projecting portion of said sleeve, said connections being of the knuckle type so that each toggle may move through a partial are relative to the wedges and the sleeve, whereby longitudinal movement of said coaxial sleeve relative to said spindle, will produce transverse movement of said wedges through the transmission of said toggle linkage so to clamp or release a draw bolt between said wedges.

References Cited in the file of this patent UNITED STATES PATENTS 725,346 Krug Apr. 14, 1903 828,695 Wellington Aug. 14, 1906 2,386,469 Iversen Oct. 9, 1945 2,485,799 Woytych Oct. 25, 1949 FOREIGN PATENTS 964,553 France Feb. 1, 1950 

